Positive Electrode Composition to Limit Battery Swelling and Cracking

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Solution Overview

Problem

Energy storage devices experience capacity decrease and swelling due to long-term charge-discharge cycles, particularly when the working voltage range is expanded, leading to cracking and decreased current collectability of positive active material particles.

Innovation Solution

Incorporating a positive active material layer containing boron and aluminum with a maximum voltage width of 1.1 V or less, which suppresses cracking and expansion of the positive active material, thereby maintaining capacity and preventing swelling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the working voltage range is expanded to increase energy density, then the energy density is improved, but the positive active material particles increase in degree of expansion and shrinkage, leading to cracking and capacity decrease

Engineering Contradiction:

Improveenergy densityVSAvoidcapacity retention after long-term charge-discharge cycle

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies parameter changes by strictly controlling the working voltage range (maximum voltage width of 1.1V or less) to prevent excessive expansion and shrinkage of positive active material particles. This parameter control resolves the contradiction by maintaining reliable capacity retention while still achieving adequate energy density through optimized voltage operation rather than excessive voltage expansion.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by incorporating both boron and aluminum into the positive active material layer. This composite approach enhances the structural stability of the positive active material particles, reducing cracking during charge-discharge cycles. The synergistic effect of boron and aluminum allows the material to withstand voltage fluctuations better, thereby maintaining capacity retention while enabling expanded working voltage ranges for higher energy density.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If the working voltage range is expanded, then the energy density is improved, but the positive active material layer expands and causes swelling of the energy storage device

Engineering Contradiction:

Improveenergy densityVSAvoiddevice swelling

Core Design Contradiction:

Use of energy by moving objectVSShape

Solution Approach 1:

The patent controls the maximum voltage width to 1.1V or less, which limits the degree of expansion of the positive active material layer. This parameter control prevents excessive swelling of the energy storage device while maintaining adequate energy density through optimized voltage operation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The inclusion of boron and aluminum in the positive active material layer creates a composite structure that constrains layer expansion. This composite material approach maintains the structural integrity of the positive electrode, preventing device swelling even when operating at expanded voltage ranges for higher energy density.

Inventive Principle:

Principle #40Composite materials

3Reliability

If boron and aluminum are incorporated in the positive active material layer, then cracking and capacity decrease are improved, but the device complexity increases

Engineering Contradiction:

Improvecapacity retention after long-term charge-discharge cycleVSAvoidmaterial composition complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a composite material approach by incorporating boron and aluminum into the positive active material layer. While this increases material composition complexity, it significantly improves capacity retention by preventing particle cracking during long-term charge-discharge cycles. The performance benefit justifies the increased material complexity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by specifically adding boron and aluminum to the positive active material layer where they are most needed to prevent cracking. This targeted approach improves reliability at the critical location (positive electrode) without unnecessarily complicating the entire device structure.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12451486B2Energy storage device and energy storage apparatus

Publication Date: 2025.10.21 GS YUASA INT LTD

AI summary

An energy storage device according to an aspect of the present invention includes: a positive electrode including a positive active material layer; a negative electrode; and a nonaqueous electrolyte, the positive active material layer includes boron and aluminum, and a maximum voltage width that is a difference between a charge upper limit voltage and a discharge lower limit voltage under normal usage is 1.1 V or less.